Currently, 948 of the total 4,224 miles of freeway in California are open to bicycles. Often, bicyclists need access to freeways to reach their destinations. Current Caltrans policy states, “when a suitable alternative route does not exist, a freeway shoulder may be considered for bicycle travel.” As a multimodal agency, Caltrans should make some modest efforts to accommodate bicycle travel on freeways in prudent circumstances. The purpose of this study is to attempt to clarify some of the issues pertaining to bicycles on freeways. Specifically, the goal of this project is to “develop policy recommendations, guidelines, and policies for bicycle and pedestrian use of freeways, expressways, tunnels, and toll bridges in California.” The initial efforts were to attempt to establish a precedent for bicycle and pedestrian use of freeways. This was accomplished by both a literature search and a survey of other Departments of Transportation (DOTs) and toll road authorities. Of 17 respondents, 15 reported having specific policies regarding bicycle use of freeways, yet only three allow bicycles access to freeway shoulders. In regard to pedestrian use of freeways, 10 out of 13 respondents replied that they have specific policies related to pedestrian use of roadways. Fourteen respondents stated that pedestrians were not allowed to travel on freeway shoulders. The Nebraska DOT was the only respondent to state that pedestrians were allowed on “any highway other than the Interstate.” The literature review found some statistical data relating to collision occurrence and was supported by research done in this study. Data are somewhat clouded by the fact that only a small percentage of the total bicycle-involved collisions are reported to the police (one survey reported 29 percent of all highway bicycle collisions), but trends still can be seen. Because bicycle traffic is relatively low, bicycle collisions are rare, especially on freeways. The table below shows some collision rates developed in this study and some found through the literature search. Rates labelled “reported” are based on formal traffic collision reports. The others are based on surveys of bicyclists. The specific circumstances involved in each collision are also important to studying bicycle collisions. Observing large groups of collisions may make it possible to develop trends and thereby identify ways to improve safety. A study of bicycle-related collisions on freeways in Caltrans Districts 1, 2, and 3 provided the following results. A total of 41 collisions occurred on the freeway in the nine years of study (1990-1998). Bicycle-motor vehicle collisions accounted for 61 percent of all collisions in the study. The bicyclist was found to be at fault by the reporting police officer in 73.2 percent of the collisions. The two most prevalent causes of bicycle-motor vehicle collisions were improper turns (29.3 percent) and the influence of alcohol (19.5 percent). A high percentage of collisions involved injury (85.4 percent); 7.3 percent of reported collisions were fatal. There was a fairly even distribution of collisions that occurred on freeways that allowed bicycle access (61 percent) versus freeways where bicycle access was A similar study was made regarding pedestrians on freeways in Caltrans Districts 2 and 3. A total of 327 pedestrian collisions occurred on freeways in these districts from 1990 through 1998. The majority (64.5 percent) involved pedestrians who had left a motor vehicle. Motor vehicles were most commonly found to be at fault, at 61.5 percent. Speeding was the primary collision factor associated with pedestrian collisions, at 35.8 percent. A total of 70.6 percent of collisions were reported as involving injury; 24.5 percent of collisions were reported as fatal. Snow was a major factor in pedestrian collisions, with 26.3 percent occurring in icy conditions. Of the collisions studied, 53.2 percent were the result of pedestrians being struck while assisting a disabled vehicle. During the course of this study, Caltrans conducted a survey of bicyclists over the Internet. Several questions tailored specifically to this study were added to the survey. Some collision rates were derived from the data, and information was compiled regarding the percent of injury collisions, percent involved with motor vehicles, and percent reported to law enforcement agencies. The table below presents some results from the 1,239 usable surveys. The respondents individually classified their position as to highway or non-highway To address questions of the safety record of bicycles on bridges, the collision history of some structures was studied. A collision ratio was established by dividing the number of collisions reported on all structures over a nine-year period by the total length of structures. Two similar ratios were derived for the approaches to the structures. One was for 500 feet on either side of the structure, and the other was for 5 miles. The 5-mile approach was used only for bridges and tunnels under Caltrans jurisdiction. The collision ratio for all structures was 0.62 collisions per mile during the 9-year period. The 500-footapproach collision ratio was 2.6 collisions per mile. For Caltrans bridges and tunnels only, the collision ratio was 0.84 collisions per mile. The 5-mile approaches had a collision ratio of 1.06. Although the data includes very few collisions, it shows that bicycle collisions on bridges and tunnels are rare events. This can be due to a number of reasons, but the data compiled here do not indicate that bridges and tunnels currently open to bicycles have more frequent collisions than the adjacent highways. In a statistical analysis of all collisions on freeways, the independent variable of Bicycle Status (bicycles permitted or prohibited) was used to attempt to predict collision rates on freeways. Bicycle Status was not found to be an adequate predictor of collision history to the 5 percent level. The lack of Bicycle Status as a significant variable suggests that allowing bicycles on freeways does not have an adverse effect on vehicle collision rates. Under the current configuration, the Richmond-San Rafael Bridge is not suited for bicycle access, but with minor alterations, bicycles might be able to travel on the shoulder safely. The following is provided as an example of what would need to be done if the bridge were opened to bicycles. Railing requirements for the Richmond-San Rafael Bridge may be given special consideration due to their width and their location relative to the travelled way. Only slight modifications to the railings, if any, would be needed to make the bridge ready for bicycle travel. Expansion joints would have to be covered to prevent bicycle wheel entrapment. The Richmond-San Rafael Bridge fits the 8-foot shoulder requirement. Currently, the bridge has 12-foot shoulders over most of the span. The wide shoulders enable bicycles to travel well separated from both motor vehicles and the bridge rail. The 12-foot space does create a problem, in that motor vehicles have been observed using the shoulders for travel and passing. One permanent section has a narrow shoulder, and due to the upcoming seismic retrofit construction, there will be some semi-permanent obstructions to the shoulder. Bicycle access should not be granted while there are sections of the shoulder closed to travel and until a continuous 8-foot shoulder can be maintained. Despite these barriers, the bridge is suited to bicycles in that bicycles could access the bridge without crossing freeway ramps. Direct connections to avoid ramp crossings by bicycles would have to be added. The recommendations developed by this study include user education, data collection, age restrictions, shoulder geometry, and procedures to allow bicyclists to cross ramps. Key recommendations are offered here in bold face type. Additional information on the recommendations can be found in Chapter 7 of this report. (Author/publisher)
Abstract